X-ray apparatuses are widely used for healthcare and the research of Basic Sciences, such as medicine, life sciences, Nondestructive Testing. A high-voltage medical power supply device is the core of the X-ray apparatus, which provides high voltages to generate X-Ray. The high-voltage medical power supply device have wide output voltage ranges, so that the X-ray apparatuses used in diagnosis can meet the imaging requirements of different people and different parts of the body.
It is essential for the X-ray apparatus to decrease its size and weight. One way is increasing the operation frequency of the high-voltage medical power supply device. The operation frequency can be observed on the high voltage output. In diagnosis X-ray apparatus, the high-voltage medical power supply devices have a positive output voltage +HV and a negative output voltage −HV, and the positive output voltage +HV and the negative output voltage −HV are superposed to obtain a high output voltage Vo. By this way, the ripple of the output voltage Vo will be added. FIG. 1 shows ripple diagrams of +HV, −HV and Vo. As illustrated in FIG. 1, the output voltage Vo has high ripple, the peak of which is approximately twice as much as that of the positive output voltage +HV or negative output voltage −HV. To the X-ray apparatus, the output voltage with high ripple will decrease the imaging precision and the image quality. So reducing the ripple of the output voltage provided by the high-voltage medical power supply device and improving the imaging precision are urgent issues to be solved in the X-ray apparatus.